The present invention relates to the field of containers and dispensers, and more particularly to an inexpensive container/dispenser for adhesives, sealants, and the like, which cure by exposure to the atmosphere or water vapor, such as RTV silicon rubber products.
Silicone polymers are in wide use today in a variety of industrial and home applications. These silicons typically can be formulated to vulcanize at room temperatures (RTV). One common type of silicon rubber cures with moisture from the air. See, e.g., "Plastics Chemistry and Technology," Walter E. Davis, Litton Educational Publishing, Inc., 1979, Chapter 6, pages 74-86, incorporated herein by this reference.
RTV silicon rubber products are typically packaged for household use in squeeze tubes having a dispenser nozzle, on which is fitted a dispenser cap. Since these adhesives cure by exposure to moisture from the air, the dispensers must be sealed against air and water vapor. The nozzle tip is sealed at the factory, and the user typically forces an opening in the nozzle by a pin or other pointed object. After squeezing out the desired amount of the adhesive, the tube is resealed by the cap. Typically, however, the adhesive filling the nozzle may cure even after the cap is replaced, making it more difficult to later reopen the nozzle opening to release additional sealant.
There are many applications which require only a small portion of adhesive or sealant, for example, assembling a product provided in kit form. Many household applications for silicon rubber sealants also require only a small portion of the sealant. Many manufacturers would prefer to include all the necessary materials to assemble or finish the product with the product kit, so that the customer need not make a separate purchase of items required for assembly, including sealants. Yet it would be expensive and/or wasteful to include a conventional squeeze tube containing the sealant due to the expense of the container and because most containers hold far more sealant than required for the job at hand.
Use of small conventional squeeze tube containers for packaging small quantities of silicon rubber sealant is understood to have met with problems of moisture leakage; the integrity of some small tubes is understood to have been poor enough that the entire contents of the tube have cured due to moisture leakage into the container.